Paper Conference

Proceedings of BSA Conference 2015: Second Conference of IBPSA-Italy


Modelling of domestic fine particles indoor exposure, its main sources and potential mitigation measures: the case of Beijing

Sandra Stefanovic, Žarko Stevanovic

Abstract: This paper presents a case study with an aim to examine the indoor impact of fine particles with a maximum aerodynamic diameter of 2.5 microns (PM2.5) and evaluate its main sources of generation within one typical residential dwelling of Beijing’s housing stock in order to define optimal mitigation measures. Based upon available data, through the validated multi-zone indoor air quality (IAQ) model the relationship between impact of indoor/outdoor factors and indoor mass concentration of PM2.5 was examined. As a referent dwelling, one of Beijing's housing stock representatives was selected. Its key parameters were combined and modelled in order to create the universal framework consisted of five baseline typical housing stock cases. The main modelling drive parameters were physical and mechanical dwelling performances: five envelope’s permeability (p) values (10, 20, 30, 40 and 50 m³/m²/h @50Pa) and different types of ventilating, throughout the year (heating and nonheating period). The simulation results suggest that under present day conditions, average indoor concentrations of PM2.5 are appreciably higher than the outdoor annual average value of 102μgm-3 because of indoor sources. In the case of naturally ventilated dwellings during heating period, cooking represents the largest contributor, generating particulate matter at concentrations four times greater than annual average outdoor mass concentration of PM2.5. Modelling demonstrated that removal of PM2.5 generated by cooking activity depends on the type of ventilation and most important on its use pattern. Furthermore, modelling provided fundamental data for evaluating indoor pollutant reduction measures. Based on previous analysis, following mitigation measures are analysed: increased EF capacity and its period of use, kitchen isolation (by closing the door) from the rest of dwellings and change of occupant behaviour regarding smoking activity. Compared to the naturally ventilated dwelling in winter period, analysed measures could decrease average indoor PM2.5 mass concentrations by almost 50%. This kind of method was found to be suitable for questioning different measures of improvement and the way for this framework to be easily broadened to the bigger scale, at the urban level.
Pages: 423 - 430